Technical Service Bulletin 520113 — 2014 BMW 640I

"Front Crash-Active Headrest Has Limited Height Adjustment. INFORMATION This bulletin will help you understand the features of the crash-active headrest and explain the benefits to your customers and center staff. 1. Learn the safety features and operation of the front seat and crash-active headrest. Photos A and B: In the event of an accident, the rear passenger must be able to move the front seatback forward, regardless of the seat position. This allows the rear passenger an easy exit from the rear seat of the vehicle, even if the electrical power source is no longer available. 2. When the seatback is manually moved, the headrest must have free movement throughout the full range of the seatback. Photos C and D: The headrest and seatback must be able to move fore and aft without contacting the roof or sun visor, regardless of seat position. The headrest height will automatically adjust to maintain this clearance, regardless of seat position. 3. In case of an accident, the crash-active headrest will be automatically activated forward to reduce the distance between the occupant's head and the headrest. This results in increased safety for the occupant. Photo E shows the headrest in the normal position. Photo F shows the headrest in the ""active"" position and will not contact the roof. Note: The headrest's chrome bar supports can be seen."